1. Field of the Invention
The present invention relates to circuit interrupters generally and, more specifically, to those kinds of circuit interrupters having a housing with a cover securable to a base.
2. Description of the Prior Art
Molded case circuit breakers and interrupters are well known in the art as exemplified by U.S. Pat. No. 4,503,408 issued Mar. 5, 1985, to Mrenna et al., and U.S. Pat. No. 5,910,760 issued Jun. 8, 1999 to Malingowski et al., each of which is assigned to the assignee of the present application and incorporated herein by reference.
A continuing industry objective with respect to many types of circuit interrupters is to be able to reduce the size and/or footprint of the interrupter housing while at the same time providing the same or improved performance capabilities. A major advantage of creating such a "smaller package" is that it provides increased flexibility in installation. However, a consequence of this objective is that the internal space constraints of such interrupters have become much more limiting, posing certain design obstacles that need to be overcome.
When the contacts of a circuit interrupter are opened during high current conditions, arcing and hot gases may be generated that raise the internal pressure within the interrupter. This pressure exerts an outward force on the housing of the interrupter that can cause the housing to bow outwards or even break apart. This is especially true in circuit interrupters having the aforementioned internal space constraints, wherein the contacts may be closer to the walls of the housing.
It would be advantageous if a way existed by which to conveniently and effectively vent the housing during such high pressure situations so that the outward force exerted on the housing is reduced.